Dyestuff solution for acrylic fibers

ABSTRACT

1. AN IMPROVED DYESTUFF SOLUTION SUITABLE FOR THE ENHANCED DYEING OF ACYLIC AND MIXED ACYLIC FIBERS AND FABRICS, SAID SOLUTION CONSISTING ESSENTIALLY OF: (A) A WATER:SOLUBLE COMPLEX OF A CATIONIC DYE WITH A LINEAR ALKYLARYLSULFONIC ACID SURFACE ACTIVE AGENT SAID SURFACE ACTIVE AGENT BEING PRESENT IN EXCESS OF THE STIOCHIOMETRIC AMOUNT FOR SAID COMPLEX; 8B) A LOWER ALCOHOLIC SOLVENT PRESENT IN AN AMOUNT WITHIN THE RANGE OF FROM ABOUT 5% TO ABOUT 25% BY WEIGHT BASED ON THE TOTAL WEIGHT OF SAID COMPLEX AND SAID ALCOHOLIC SOLVENT; (D) AN ALKALIZING AGENT PRESENT IN AN AMOUNT SUFFICIENT HAVING 1 TO 3 CARBON ATOMS, SAID CHLORINATED HYDROCARBON SOLVENT BEING PRESENT IN AN AMOUNT SUCH THAT THE DYESTUFF SOLUTION CONTAINS FROM ABOUT 0.1 TO ABOUT 20 PARTS BY WEIGHT OF SAID COMPLEX PER 100 PER PARTS OF SAID HYDROCARBON SOLVENT; (D) AN ALKALIZING AGENT PRESENT IN AN AMOUNT SUFFICIENT TO SSURE THAT THE PH OF SAID DYESTUFF SOLUTION IS FROM ABOUT 2 TO ABOUT 7.5; AND (E) WATER PRESENT IN AN AMOUNT SUFFICIENT TO FORM A CLEAR, STABLE SOLUTION OF THE COMPLEX IN SAID SOLUTIO CONTAINING SAID CHLORINATED HYDROCARBON SOLVENT AND SAID LOWER ALCOHOLIC SOLVENT, WHEREBY THE RESULTING CLEAR, STABLE DYESTUFF SOLUTION IS CAPABLE OF PRODUCING A GREATER DEGREE OF BRIGHTNESS THAN CONVENTIONAL AQUEOUS DYESTUFF SOLUTIONS, THE SHORT DYEING TIME ACQUIRED WITH SAID DYESTUFF SOLUTIONS, THE SHORT DYEING AGE TO THE FIBER BEING DYED AND PERMITTING INCREASED DYED FIBER PRODUCTION.

DYESTUFF SOLUTION FUR ACRYLIC FIBERS Clemens Streck, Loudonville, N.Y., assignor to GAE Corporation, New York, N.Y.

No Drawing. Filed Dec. 21, 1970, Ser. No. 100,536 Int. Cl. Dtlfip 5/04 U.S. Cl. 8-159 5 Claims ABSTRACT OF THE DISCLOSURE A continuous solvent dyeing process for the solvent dyeing of polyacrylic and similar fibers is provided utilizing a clear, stable solution obtained by complexing basic dyes with linear alkylarylsulfonic acid surfactants in a solvent mixture of a lower alcoholic solvent and an alkalizing agent. In carrying out the dyeing process, the clear solution of the basic dye complexed with linear alkylarylsulfonic acid surfactant is mixed with a lower alkyl water-insoluble chlorinated solvent.

This application is directed to a continuous solvent dyeing process for the dyeing of polyacrylic and similar fibers; more particularly, the present invention is directed to such a continuous solvent dyeing process utilizing a solution of a complex of a basic dye with a linear alkylarylsulfonic acid surfactant in a solvent mixture of a lower alcoholic solvent and an alkalizing agent.

Acrylic fibers have the common characteristic that such fibers are all hydrophobic. Such hydrophobic polymers are difficult to dye with many of the usual types of commercially available dyestuffs by pad thermofixation, particularly to uniform deep shades. As a result, in the past, many fabrics made therefrom have only been available in pastel shades.

While the cationic dyes have greatly improved the dyeing ability of the acrylic fibers, the industry has still sought to improve the dyeing of such materials by development of faster and more economical processing operations.

In 1949, the Thermosol process of dyeing was developed by Du Pont for commercial thermofixation of dispersed dyes on polyester fibers. This method led the way in the general direction of producing a faster and more economical processing operation by offering a continuous dyeing system for synthetics which allowed speed of operation parallel to that obtained on natural fibers with conventional processes such as the Williams unit or padsteam processes. This thermofixation process is now well established for the dyeing of certain synthetic fibers and fabrics in the dyeing industry, but its use With cationic dyes for acrylic fibers has so far been unsuccessful. This process basically comprises a continuous method for dye ing fibers, fabrics, etc. by a brief exposure of such material to high temperatures. Thus, for example, temperatures of approximately 375-430 F. for 30 seconds to 3 minutes are conventionally utilized in a T hermosol process to thermofix the dispersed dye in the dyeing of polyester fibers etc.

While such a process also has aided the dyeing of acrylic and other synthetic materials, such process possesses disadvantages which prevented commercial acceptance.

Dispersed dyestuffs can be thermofixed on acrylic fibers, but such dyestuffs cannot be built up to medium and heavy depth, and also, their fastness is generally not sufficient for most uses. While cationic dyestuffs also thermofix on acrylic fibers and in some cases yield good results, there are certain inconveniences present again with the employment of such materials. These include, for example, lack of buildup, incompatibility and sensitivity to other classes of dyes and chemicals that may have to be United States Patent O used to assist the operation or to dye other components of a multifiber blend, and, a heavy staining of the equipmen that is used in the application of cationic dyestuffs on acrylic fibers. Thus, for example, pad rolls, frame clips, etc. become so heavily stained that cleaning between different runs becomes a major and costly operation in the employment of cationic dyestuffs.

The padding of dispersions of insoluble complexes maintained in dispersion by the addition of a non-ionic surfactant have formed the basis of other proposals. Such a system has the disadvantages of requiring the employment of an additional nonionic surface active agent in order to create a stable dispersion of the insoluble complex formed between the cationic dyestuif and the anionic retarding agent. While such a method produces some satisfactory results, the process is selective as to the dyestuif that can be employed and the system itself is extremely delicate and very diificult to use industrially with success.

It has also been proposed to employ specially dispersed dyes (Du Pont Sevron T pastes) that form salts in situ with the anions of the fiber during thermofixation. This salt formation does not occur properly, however, unless the fabric has been pro-treated (preferably at the boil) with a concentrated solution of ammonium sulfate to replace the fiber polymer anionic groups with an ammonium radical. The ammonium radical, under thermofixation conditions, splits off and allows the fast linkage of the dye to the fiber. In industrial practice, however, this system is not satisfactory. It did not prove economically advantageous because of the necessity of a pretreatment of the fiber before the dyeing operation. It is also a delicate process which involves careful control at an industrial level. Therefore, such a process has not been adopted with success.

Due to the problems that have been encountered in previous attempts to dye acrylic fibers, basic dyes have been used extensively in the dyeing of these materials. Accordingly, recent developments in the field of dyeing have led to the greater use of basic dyes in the dyeing of newer synthetic fibers such as polyacrylonitrile and mixed fibers containing the same as well as fibers derived therefrom.

In addition to the ever increasing use of basic dyes, still more interest has been created. in the production and use of solutions of such dyeing materials. In this regard, when the dyer obtains a dyestuff in solution form he does not have the problem that the dye house is polluted with flying pulverulent dyestuff as would be the case when the dye is provided in a powdered or pulverulent form. In this regard, when the dye is supplied to the ultimate user in such a powdered or pulverulent form it is generally necessary that the user first form a paste, reduce the paste to the desired strength, and subsequently dilute the reduced paste prior to eventual use: thereof. Accordingly, it should be quite clear that it is much easier and advantageous to dilute a concentrated solution to desired strength prior to ultimate use than it is to start from a powder or similar form which has to go through the aforementioned stages. In this regard, a concentrated solution of dyestuff can be diluted and readily metered for use or can even be metered as it is diluted for use. Accordingly, it is quite clear that the preparation of stable, clear concentrated solutions of basic dyes adapted for the dyeing of acrylic fibers provides a great advantage over previously developed forms.

While the preparation of such clear, stable concentrated solutions of basic dyes adapted for the dyeing of acrylic fibers is the ultimate goal, it must be pointed out that it has been found difficult to date to produce completely satisfactory solutions or liquids of basic dyes. This is because it is frequently extremely difficult to obtain dyestulf solutions or liquids which are in concentrated form that will not haze or precipitate out during storage.

In this regard, it is quite obvious that the preparation of the dyestuff solution in a concentrated form is advantageous so as to minimize shipping costs and to minimize storage facilities. However, as indicated above, it is frequently very diflicult to provide such concentrated solutions which will be stable under the adverse temperature and time conditions of transportation and storage. In this regard, if such hazing or precipitation of the concentrated dyestuff solution occurs the solution changes its form and specking of the dye material frequently occurs. This, of course, is a disadvantage which cannot be tolerated with todays requirements of uniformly-dyed products.

In accordance with the present invention, it has been discovered that acrylic fibers and fabrics can be very effectively dyed in a solvent dyeing process by utilizing a clear, stable solution of a cationic dyestuff complexed with a linear alkylarylsulfonic acid surface-active agent mixed with a lower alkyl water-insoluble chlorinated solvent. In this regard, it has been discovered in accordance with the present invention, that the dyeings which can be achieved by the use of such a solvent system are brighter than dyeings obtained with a conventional method of dyeing utilizing an aqueous system. Additionally, water pollution is eliminated during dyeing since solvent recovery is practical in commercial operations. Also, since dyeing time is shorter, damage to the fiber can be minimized and production accordingly increased. Moreover, in the case of a mixed polyacrylic viscose fabric, when utilizing the dyeing process of the present invention, the viscose is considerably less stained than when dyed by use of conventional aqueous system.

Thus, wherein dyestuff solutions have been previously diluted to the desired strength with water and thickened to desired padding or printing viscosity with thickeners, it has been discovered in accordance with the present invention, that the foregoing advantages can be achieved by the solution dyeing with a solution of the soluble complex mixed with a lower alkyl water-insoluble chlorinated solvent.

Accordingly, it is a principal object of the present invention to provide a novel process for the dyeing of acrylic fibers and fabrics as Well as a novel composition for use therein, such process and composition eliminating and avoiding all of the disadvantages and deficiencies of the prior art.

It is yet a further object of the present invention to provide a novel process and composition for the solvent dyeing of acrylic fibers and fabrics wherein the dyestuff comprises a stable complex of a cationic dyestulf with a linear alkylarylsulfonic acid surface-active agent, such complex being produced in a solvent mixture of a lower alcoholic solvent and an alkalizing agent.

It is yet a further object of the present invention to provide such a process for the dyeing of acrylic fibers and fabrics wherein said process is a solvent process, utilizing a clear, stable solution of a complex of a cationic dyestutf with a linear alkylarylsulfonic acid surface-active agent mixed with a lower alkyl water-insoluble chlorinated solvent.

Still further objects and advantages of the novel process and composition of the present invention will become more apparent from the following more detailed descrip tion thereof.

The foregoing objects and advantages of the present invention are achieved by admixing a water-soluble complex of a cationic dyestutf and a linear alkylarylsulfonic acid surface-active agent with a lower alkyl water-insoluble chlorinated solvent and thereafter dyeing an acrylic fabric therewith. Thus, while in past practice the dyestutf solutions were diluted to desired strength with Water and thickened to the desired padding or printing viscosity with thickeners, such dilution with water is not conducted in accordance with thepresent invention, but a solvent system is prepared which can be easily and very satisfactorily used to dye acrylic fibers and fabrics. In this regard, it has been discovered in accordance with the present invention that dyeings obtained in accordance with the instant process are 'brighter than similar colors obtained in a normal method of dyeing employing an aqueous system. Moreover, it has been discovered in accordance with the present invention that where a mixed polyacrylic-viscose fabric is dyed, the viscose is considerably less stained when utilizing a solvent dyeing process in accordance with the present invention than when utilizing a conventional aqueous system.

As indicated above, the dyestuff of the present invention is in the form of a clear, stable solution of a basic dye complexed with a linear alkylarylsulfonic acid surface-active agent. In this regard, in order to produce such complexes that will liquify readily and produce liquids that are sufficiently concentrated and stable to be used in commercial dyeing, it has been found that only linear alkylarylsulfonic acids can be utilized as the anionic portion of the complex. The anionic portion in accordance with the present invention thus comprises a linear alkylarylsulfonic acid surface-active agent and the .same should not be confused with an anionic dyestuff. In this regard, the anionic portion of the complexes utilized in accordance with the present invention would not themselves possess dyeing characteristics. The linear alkylarylsulfonic acid surface active agents utilized in accordance with the present invention are generally C to C alkylarylsulfonic acids wherein the aryl moiety is selected from benzene, diphenyl and naphthyl series. Accordingly, exemplary linear alkylarylsulfonic acids, suitably used in accordance with the present invention include such as:

nmonylbenzenesulfonic acid n-dodecylbenzenesulfonic acid n-hexadecylbenzenesulfonic acid n-octadecylbenzenesulfonic acid n-tridecylbenzenesulfonic acid n-nonyldiphenylsulfonic acid n-dodecyldiphenylsulfonic acid n-nonylnaphthalenesulfonic acid.

The above exemplary linear alkylarylsulfonic acid surface active agents as well as various others falling within such description are commercially available under various trade names. Thus, for example, such linear alkylarylsulfonic acid surface active agents in the form of specific compounds and blends or mixtures thereof as the acid or alkali metal salts of the acid are sold as:

Nacconol 98 SA (Allied Chemicals) Calsoft LAS-99 (Allied Chemicals) Conoco C-SSO (Continental Oil Co.) Conoco C-650 (Continental Oil Co.) Dowfax 2A 1 (Dow Chemical Co.) Dowfax 3B 1 (Dow Chemical Co.) Emkal NNS (Emkay Chemical Co.) Gardilene S (Albright and Wilson) Hartofol BD (Hart Products Corp.) Hipochem 40-LA (High Point Chemical Corp.) Nansa HS S (Albright and Wilson) Nansa TDB (Albright and Wilson) Nekal NF (GAF Corp.)

Nyapon W (Nyanza, Inc.)

Orvas AB (Procter and Gamble) Petro SWPX (Petrochemicals, Inc.) Richonate 40B (Richardson Co.) Santomerse ME (Monsanto) Soropon SF (GAP Corp.)

Sulfrarnic Acid 1298 (Witco Chemical Corp.) Sulframine 40 (Witco Chemical Corp.).

The cationic dyes employed in the process of the present invention can be any of the different types of cationic or Bas1c dyes employed in the dyeing of fibers and fabrics and acrylic fibers and fabrics in particular. The following basic dyes, classified by types are suitable for the preparation of the dyestuffs of this invention:

Sevron Blue 2G.

Sevron Yellow 3RL Caloozine Acrylic Yellow G. Sandocryl Yellow B-4RL- Sevron Orange L Sevron Brown YL Calcozine Acrylic Orange 3R.

lllllllll AAICO 0.1. prototype Class and name number designation Triphenylmethane:

Methyl Violet 42535 Basic Violet 1.

Magenta ABN 42520 Basie Violet 2.

Crystal Violet 42555 Basic Violet 3.

Fuohsine N 42510 Basic Violet 14.

Genaeryl Blue 42025 Basic Blue 1.

Rhoduline Blue 5B 42140 Basic Blue 5.

Genacryl Blue 5B 42140 Basic Blue 5.

Victoria Pure Blue B 42595 Basic Blue 7.

Victoria Blue BS..- 44045 Basic Blue 26.

Brilliant Green B 42040 Basic Green 1.

Victoria Green S 42000 Basic Green 4. Oxazine:

Genaeryl Blue 3G 51005 Basie Blue 3.

Sevron Blue 56... 51004 Basic Blue 4.

Basic Navy Blue D- 51175 Basic Blue 6.

Nile Blue BXA 51180 Basie Blue 12. Anthraquinone:

Sevron Blue B Basic Blue 21.

Basic Blue 22.

Sevron Violet B Basie Violet 24. Sevron Blue BGL Basic Blue 35. Astrazon Blue CSGL. Basic Blue 45. Astrazon Blue 3RLW Basic Blue 47. Thiazine:

Methylene Blue 52015 Basic Blue 0. New Methylene Blue A. 52030 Basic Blue 24. Calcozine Green 52020 Basic Green 5. Acridine:

Euchrisine GGNY 46040 Basic Yellow 9. Flavo Phosphine R. 46035 Basic Orange 9. A Basic Yellow 3R 46005 Basic Orange 14.

Bismarck Brown 21000 Basic Brown 1. Basic Leather Brown 5R. 21030 Basie Brown 2. Paper Brown T 21010 Basic Brown. Cyper Black 1A Basic Black 3. Indazol Blue R... 12210 Basic Blue 16. Acridine Orange N- 46005 Basic Orange 14. Chrysoidine RS.--" 11320 Basic Orange 1. Chrysoidine Y Extra. 11270 Basic Orange 2.

Basic Yellow 15. Basic Yellow 26. Basic Yellow 32. Basic Orange 24. Basic Orange 26. Basic Orange 31.

Sevron Red L Basic Red 17. Sevron Red GL Basie Red 18. Sandoeryl Red B- Bas c Red 23. Calcozine Acrylic Bas e Bed 30. Calcozine Acrylic Violet 3R. Basic Violet 18. hiazole; Thioflavine 49005 Basic Yellow 1.

iphenylmethane (ketonimine):

Auramine 41000 Basic Yellow 2. Basic Yellow AR. 41001 Basie Yellow 37. Auramine G 41005 Basic Yellow 3. anthene:

Rhodamine 6G 45160 Basic Red 1. Rhodamine G. 45150 Basic Red 8. Rhodamine B 45170 Basic Violet 10. Methine:

Genacryl Orange G 48030 Basic Orange 21. Genacryl Orange R. 48040 Basic Orange 22. Genacryl Pink G... 48015 B21510 Red 13. Genaeryl Red 6B... 48030 Basic Violet 7. Genacryl Yellow 401.. 48055 Bas c Yellow 11. Gcnacryl Yellow 5G.... 48065 Bas c Yellow 12. Astrazone Yellow 7GLL. Basie Yellow 21.

Basic Yellow 28. Basic Red 13.

Astrazone Golden Yellow GL. Genaeryl Pink G.

The above list is representative of cationic dyes that can be advantageously employed in the process of the present invention. It is, of course, to be understood that any suitable cationic dye that is advantageously employed in the dyeing of fibers and fabrics and particularly acrylic fibers and fabrics can be advantageously employed in the production of the water-soluble complex in accordance with the present invention. '1

For tinctorial strength, it is preferred that the cationic dye employed in the production of the complex be an unstandardized dye. In this regard, for example, where a standardized dye is employed in the formation of the complex, it is generally necessary to allow for the reduced strength of the dye by the addition of larger amounts of dye in connection with the formation of the complex. The cationic dyestuff-linear alkylarylsulfonic acid surfaceactive agent complexes may be produced in accordance with the present invention in situ by mixing the dye and linear alkylarylsulfonic acid surface-active agent in a suitable solvent mix. The temperature of mixing is usually that of room temperature but heating is not necessary as the reaction for complex formation is mildly exothermic.

When the complex is prepared in situ as set forth above, the same is generally prepared by mixing one part of the cationic dye with a slight stoichiometric excess of the surface-active agent, up to about 10 parts of surface-active agent being advantageously utilized. It is to be understood, however, that even greater excesses of the linear alkylarylsulfonic acid surface active agent can be employed, but the limitation set forth above is merely one of economics. Thus, the addition of greater amounts of linear alkylsulfonic acid surface active agent does not in any way inhibit the formation of a clear, stable complex but merely supplies additional surface active agent when desired.

As indicated above, the complex is generally prepared in situ by mixing the cationic dyestuif and surface active agent in a suitable alcoholic solvent. Such alcoholic solvent comprises a material such as a lower alcoholic solvent such as a lower alkanol, lower alkylene glycol, or lower alkoxy alkanol. Accordingly, suitable lower alcoholic solvents employed in accordance with the present invention include such as: l

methanol ethanol propanol ethylene glycol diethylene glycol methoxyethanol ethoxyethanol (Cellosolve) and butoxy-ethanol.

When utilizing such lower alcoholic solvent as one component of the solvent mixture in the in situ production of the stable, soluble complex of the cationic dyestuff and the linear alkylarylsulfonic acid surface active agent, the lower alcoholic solvent is generally employed in an amount of from about 5 to 25 %by weight, based upon the total weight of the complex-containing solvent system.

In accordance with the present invention, it is preferred that the linear alkylarylsulfonic acid be in the free acid form since it is preferable that the pH of the surfactant be within the range of about 3 to 7 when the complex with the basic dyestuif is formed. While the sodium and similar alkali metal and alkaline earth salts are applicable in accordance with the present invention, since such salts are generally at a higher pH of about 7 to 10, it is preferred that such salts be converted to the free acid form prior to preparation of the complex.

While the pH of the complex thus formed is generally within the range of about 1 to 6, the final pH of the solution is within the range of 24.5, preferably 6-7.5. To accomplish this, the solution is alkalized by the addition of an alkalizing agent in an amount sufficient to adjust the pH of the final solution to the desired range.

As the alkalizing agent, any can be used which is capable of adjusting the pH to the desired range. Suitable alkalizing agents include such materials as lower alkylamines and lower alkanolamines; ammonium hydroxide; alkali metal hydroxides, e.g., sodium hydroxide, potassium hydroxide, lithium hydroxide; alkali metal carbonates and bicarbonates, e.g., sodium carbonates, sodium bicarbonate, potassium carbonate, potassium bicarbonate, lithium carbonate, lithium bicarbonate; magnesium oxide, etc. Of the above, the lower alkylamines and hydroxides are preferred.

The lower alkylamines employed in accordance with the present invention include lower alkyl primary, secondary and tertiary amines as Well as primary, secondary and tertiary lower alkanol amines. Thus, for example,

such lower alkylamine components of the solvent mix include such as: propylamine, isopropylamine, diisopropyla-mine, triisopropylamine, isobutylamine, monoethanolamine, diethanolamine, triethanolamine, methylaminoethanol, dimethylaminoethanol, butanolamine, pentanolamines, hexanolamines, heptanolamines and the like. These liquid lower alkyl amines are employed in amounts of from 3 to about parts of the total weight of the formulation.

As indicated previously, it has been the past practice to dilute a solution of the complex formed by the 'dye and the surfactant such as prepared by the foregoing procedure with water to the desired strength and thicken the solution to the desired padding or printing viscosity with thickeners. In accordance with the present invention, however, water is used in a minimum amount, and need not necessarily be present in the system. Water, however, is preferred and the amount of any water present is that which is necessary to produce a clear, stable solution. In order to carry out the solvent dyeing process, a portion of the preformed solution of the complex as set forth above is admixed with a lower alkyl water-insoluble chlorinated solvent. Thus to produce a system suitable for the solvent dyeing of acrylonitrile alone or admixed with other fibers such as cotton or viscose it is only necessary to admix the solvent solution of the cationic dyestuff-linear alkylarylsulfonic acid sulfate active agent complex with a lower alkyl water-insoluble chlorinated solvent.

Examples of such lower alkyl water-insoluble chlorinated solvents suitably employed in the solvent dyeing process of the present invention include such materials as:

1,2-dichloroethylene perchloroethylene 1,1,2,2-tetrachloroethylene) trichloroethylene 1,1-dichloroethane 1,2-dichloroethane 1,1,2,2-tetrachloroethane 1, 1, 1,2-tetrachloroethane 1,1,1-trichloroethane 1, 1,2-trichloro ethane tetrachloromethane trichloromethane l-chloropropane 1, l-dichloropropane 1,2-dichloropropane 2,2-dichloropropane.

In carrying out the solvent dyeing process in accordance with the present invention other additives may be included in the system such as antifoam agents, booster solvents such as dimethylformamide and the like. After preparing the solvent system by admixing of the complex solution with the lower alkyl water-insoluble chlorinated solvent the polyacrylic material or polyacrylic material in admixture with other fibers is then padded with the solution. The padding is generally conducted at room temperature and use of such ambient conditions is generally preferred. However, it is also possible to provide the desired dyeing of the polyacrylic material by the use of somewhat higher temperatures up to about 140 F. After padding with the solvent system, the material that has been dyed is dried and cured at a temperautre of from about 375 to 430 F. for a period of from about seconds to 3 minutes. The dried and cured material is then finished in conventional manner or by special solvent methods, depending on the material and the finish desired.

As indicated previously, the use of the solvent dyeing system and process of the present invention results in brighter colors on acrylics than can be obtained on such materials with the normal dyeing methods employing aqueous systems. Moreover, when the dyeing is conducted with respect to a polyacrylic-viscose fabric, the viscose is considerably less stained when utilizing the solvent system and dyeing process of the present invention than when the mixed fabric is dyed with an aqueous system. Other advantages are present, however, with the use of the solvent system and process of the present invention. Thus, for example, wetting of the fiber is faster so that there is less swelling of the fiber, and therefore, less mechanical deformation. Additionally, since the solvent can be easily recovered in the system, effluent problems from dye plants are reduced and the recoverability of the solvent provides an economic advantage over previously utilized systems when equated with the cost of full anti-pollution measures.

The novel solvent system and solvent dyeing process for polyacrylic fibers and fabrics in accordance with the present invention will now be described by reference to the following specific examples. Such examples are presented for purposes of illustration only and are in no Way to be deemed to limit the instant invention.

EXAMPLE 1 Preparation of the basic dye liquid formulation:

Some 130 parts Nacconol 98 SA (linear dodecylbenzene sulfonic acid, free acid form), 50 parts Cellosolve, 40 parts water and 27 parts monoethanolamine were mixed together. Then 50 parts Genacryl Blue 5B (Cl. 42140) and 3 parts DC Antifoam FG (commercially available antifoam agent) were stirred into the solution with the pH being adjusted to 67 with monoethanolamine. Water was added to a volume of 350 parts.

The resulting solution was clear when diluted with water, and was stable under prolonged storage conditions, i.e., did not haze or form a precipitate.

EXAMPLES 2-7 The following formulations were prepared according to the manner of Example 1.

130 10 50 50 4O 40 28 27 D0 Antifoam FG 3 3 Genacryl Pink 36 (0.1. Basic Red 14) 23 n Genacryl Yellow 4G (0 I Basic Yellow 11; 0.1. 48055). 28 28 Gtlagiacryl Red GL (0.1. 0 Red 38 Genacryl Red 3BL (0.1. Basic Red 22 Genacryl Blue SE (0.1. Basic Blue 5; 0.1. 42140) 40 Monoethanolamine to pH 6. 5 6. 5 6. 5 6. 5 6. 5 6.5 Water to 350 350 350 350 350 350 As in Example 1, clear stable liquids resulted.

EXAMPLES 8-11 The following examples were formulated in the manner of Example 1.

Nacconal 98 SA 130 130 130 Monoethanolarnine 27 27 27 27 Victoria Green (0.1. Basic Green 4; 0.1. 42000). 100

Genacryl Blue 3G (0.1. Basic Blue 3; 0.1. 51005) 35 Genacryl Red GB (0.1. Basic Violet 7; 0.1. 35

Genacryl Orange G (0.1. Basic Orange 21; 0.1. 19

Monoethanolamine to pH 6. 5 6. 5 6. 5 6. 5

Water to 450 350 350 350 As in Example 1, clear stable liquids resulted.

9 EXAMPLES 12-13 As in Example 1 the following formulations were compounded.

N acconal 98 8A..

Water Genaeryl Pink 3G (C.I. Basie Red14) Genaeryl Yellow 4G ((3.1. Basic Yellow 11; Cl. 48055) DC Antifoarn F G pH adjusted with ammonium hydroxide to pH As in Example 1 clear stable solutions were produced.

EXAMPLES 14-18 The following examples were formulated in the manner of Example 1.

Conoco 6-550, free acid Dowiax 2A 1, free acid.. Emkal NNS, free acid N ekal NF, free acid Santomerse ME, free a Cellos ve Water 68 68 Monoethanolarmne 27 27 Genaeryl Red GL 38 38 DC Antifoam F 3 3 Monoethanolamine to pH 6-7 6-7 Water 350 350 350 350 In all cases clear stable solutions were obtained.

EXAMPLES 19-22 The following examples were formulated in the manner of Example 1.

Nacconal 98 SA. Ethanol In all cases good stable solutions were obtained.

EXAMPLES 23-27 The following solutions were prepared consisting of 3.0 oz. of liquid and 1 gal. perchloroethylene.

Liquid from Dye Example N 0.

23 Genaeryl Blue B 1 2 9 5 Orlon-viscose fiber (50:50) was padded at room temperature with these solutions, dried, and cured 1 minute at 400 F., then rinsed and dried.

The Orion was dyed in bright dyeings with little or no stain on the viscose. This is in contrast with Orlon-viscose dyed in the same manner from an aqueous bath wherein the viscose was heavily stained and the Orlon dyeings were not as bright.

EXAMPLES 28-29 Genacryl Pink G (C. I. Basic Red 13, C. I. 48015) and Genacryl Blue 66 (C1. Basic Rule l, C.I. 42025) were made into solutions in the manner of Example 1. These solutions were then combined with water and perchloroethylene in the manner of Examples 23-27 and dyed in the same manner. The Orion dyeings were brightly colored, and the viscose relatively unstained.

1 0 EXAMPLE 30 The dyestuif having the formula:

CH3 mac... -oH on N \+N/ \C2H4CN CH. CH;

was made into a solution in the manner of Example 1, and was then made into a solvent mix and dyed in the manner of Examples 23-27. The Orlon was dyed a bright red with very little stain on the viscose.

EXAMPLES 31-32 Solutions of the following dyes were formulated in the manner of Example 1.

No: Dyestuif 31 Genacryl Red 4B (0.1. 48013).

32 Genacryl Brilliant Pink FBB (Cl. Basic Red 15).

Dyeings employing perchloroethylene were made in the manner of Examples 23-27 with commensurate results.

EXAMPLES 33-38 The solution of Example 1 was admixed with perchloroethylene in the following amounts:

Genacryl blue Perchlora- Example number solution (02.) ethylene (gaL) Dyeings carried out in the manner of Examples 23-27 resulted in excellent Orlon dyeings, the more concentrated solutions having deeper coloration.

The viscose was stained very little in all cases.

EXAMPLES 39-44 The solution of Example 1 was made into a solvent mix employing the following:

1,2-dichloroethylene (gal.).. 'lzichloroethylene (gaL) 1,2-diehloroethane (gaL) 1,1,2,2-tetraehloroethane (gal) Tetraehloromethane (gaL) 1,2 dichlor0peopane (gaL) When dyeings were carried out in the manner of Examples 23-27, bright dyeings on Orlon were obtained which had little to no coloration on viscose. The dyeings were brighter and cleaner than the related dyeings employing only the accepted aqueous method of application.

EXAMPLES 45-48 The basic dye liquid formulations were prepared following the procedure of Example 1. except that the linear alkylarylsulfonic acid surface active agent, Nacconol 98 SA, was replaced with equivalent amounts of the following materials:

Example No: Surface active agent 45 n-Hexadecylbenzenesulfonic acid. 46 n-Octadeeylbenzenesulfonic acid. 47 n-Nonyldiphenylsulfonic acid.

48 n-Nonylnaphthalenesulfonic acid.

Dyeings employing perchloroethylene were made in the manner of Examples 23-27 with commensurate results.

EXAMPLE 49 Two assistants were prepared as follows:

Parts Assistant A B Cellosolve 38 38 DO Antifoam H-lO emulsion 2 2 Sodium hydroxide 40 Be 13 Water 10.2 Magnesium oxide 2. 8 To this mixture was added slowl 47 *Sulframine Acid 1298 is a linear alkylarylsulionic acid, Witco Chem. 00.

Heat and stir to the formation of viscous solution pH 6.

The following dye complexes were produced:

Parts Assistant A Assistant B 600 Cellosolve 100 100 Water 50 50 Genacryl Yellow 4 100 100 Total 850 850 Spectral analysis showed the relative strengths to be: (1) 270/100 and (2) 270/100. They were adjusted to equal strength as follows:

Parts (1) 90 90 Oellosolve 10 (3) was fluid; (4) was more fluid.

Solutions (3) and (4) were found to dye polyacrylonitrile fabric excellently when solvent systems were prepared and utilized as in Examples 23-27.

EXAMPLE 50 Polyacrylonitrile was pad-dyed in the same manner as Examples 23 to 27 and gave excellent dyeings.

EXAMPLE 51 The following solutions were formulated:

Assistant A (from Example 49) Assistant B (from Example 49) Genacryl Red GL..-

Solvent dyeings were made in the same manner as Examples 23-27, giving excellent dyeings.

EXAMPLE 52 The following formulations were prepared:

Parts Parts Parts Parts Cellosolve 31 31 42 42 DO Antiloam H-lO emulsion 2 2 2 2 Sodium hydroxide 40 Be." 7. 7. Water 22 28. 3 11. 2 17. 3 Magnesium oxide 1. 1. 7

Sulframine Acid 1298- 28 28 28 28 Genacryl Yellow 4G 9 9 9 9 Total 100 100 100 The thus-formed solutions had excellent stability. Polyacrylonitrile fabric, dyed as in Examples 23-27, gave excellent dyeings.

These formulations were stirred to the formation of solutions. To each was then added 10 parts water, 10 parts Cellosolve, and 10 parts Genacryl Yellow 4G.

Dyeing of polyacrylonitrile fabric by a solvent dyeing process as in Examples 23-27 yielded excellent dyeings.

It can be clearly seen from the foregoing examples that the present invention comprises an improved method of dyeing acrylic and mixed acrylic fibers and fabrics as well as a solvent system therefor. Thus, the method of the present invention comprises contacting the fibers and fabrics with a solvent system comprising a lower alkyl water-insoluble chlorinated solvent and from 0.1 to 20 parts per 100 parts of said chlorinated solvent of a complex of a cationic dyestuif and a linear alkylarylsulfonic acid surface active agent dissolved in a lower alcoholic solvent, together with an alkalizing agent and Water in an amount sufficient to form a clear, stable solution of the complex. As indicated previously, such method of dyeing acrylic and mixed acrylic fibers and fabrics generally comprises contacting the fibers and fabrics with such a system at a temperature of from about room temperature up to the boiling point of the solvent system.

Moreover, the solvent system and process of the present invention have eliminated the generally used aqueous systerns which, while allowing effective dyeing, cannot produce the degree of brightness associated with the present invention. Thus, dyeings obtained by the use of the solvent system of the present invention are brighter than colors obtained in the normal method of dyeing utilizing an aqueous system and in the case of dyeing a mixed polyacrylic-viscose fabric, the viscose is considerably less stained than when dyed with an aqueous system.

Therefore, the present invention comprises a distinct improvement over those conventional aqueous systems of the prior art and provides an additional benefit in reducing a source of water pollution by dye plant efiiuent.

While the present invention has been described primarily with respect to the foregoing exemplification, it is to be understood that the present invention is in no way to be deemed as limited thereto, but must be construed as broadly as any or all equivalents thereof.

All parts and proportions referred to herein and in the appended claims are by weight unless otherwise indicated.

What is claimed is:

1. An improved dyestutf solution suitable for the enhanced dyeing of acrylic and mixed acrylic fibers and fabrics, said solution consisting essentially of:

(a) a water-soluble complex of a cationic dye with a linear alkylarylsulfonic acid surface active agenu 13 said surface active agent being present in excess of the stoichiometric amount for said complex;

(b) a lower alcoholic solvent present in an amount Within the range of from about to about 25% by weight based on the total weight of said complex and said alcoholic solvent;

(c) a water-insoluble chlorinated hydrocarbon solvent having 1 to 3 carbon atoms, said chlorinated hydrocarbon solvent being present in an amount such that the dyestufi solution contains from about 0.1 to about 20 parts by weight of said complex per 100 parts of said hydrocarbon solvent;

(d) an alkalizing agent present in an amount sufiicient to assure that the pH of said dyestufi solution is from about 2 to about 7.5; and

(e) water present in an amount sufiicient to form a clear, stable solution of the complex in said solution containing said chlorinated hydrocarbon solvent and said lower alcoholic solvent,

whereby the resulting clear, stable dyestulf solution is capable of producing a greater degree of brightness than conventional aqueous dyestulf solutions, the short dyeing time required with said dyestulf solution minimizing damage to the fiber being dyed and permitting increased dyed fiber production.

2. The dyestutf solution of Claim 1 in which suflicient alkalizing agent is present to assure that the pH of said solution is from about 6 to about 7.5.

3. The dyestutf solution of Claim 2 in which said surface active agent contains from 8 to 24 carbon atoms in the alkyl portion thereof, the aryl moiety thereof being selected from the group consisting of benzene, diphenyl and naphthyl.

UNITED STATES PATENTS 3,349,141 10/1967 Sweeney 252Dig. 6 3,718,428 2/ 1973 Streck 8-173 3,129,053 4/1964 Castle 893 3,265,461 8/1966 Luetzel 884 2,182,963 12/1939 Dreyfus 836 2,173,178 9/1939 Moncrief 8-48 1,966,391 4/1935 Straus 86 2,523,749 8/1970 McLeod 8-54.2

OTHER REFERENCES Colour Index, 2nd edition, pp. 2697, 2698, 2813, 2815, and 2816, pub. by Amer. Assoc. Tex. Chem. & Col., Lowell, Mass.

Colour Index, vol. 2, 2nd edition, 1956, pp. 2815 and 2816.

DONALD LEVY, Primary Examiner US. Cl. X.R.

8174, 177 AB, 21 A 

1. AN IMPROVED DYESTUFF SOLUTION SUITABLE FOR THE ENHANCED DYEING OF ACYLIC AND MIXED ACYLIC FIBERS AND FABRICS, SAID SOLUTION CONSISTING ESSENTIALLY OF: (A) A WATER:SOLUBLE COMPLEX OF A CATIONIC DYE WITH A LINEAR ALKYLARYLSULFONIC ACID SURFACE ACTIVE AGENT SAID SURFACE ACTIVE AGENT BEING PRESENT IN EXCESS OF THE STIOCHIOMETRIC AMOUNT FOR SAID COMPLEX; 8B) A LOWER ALCOHOLIC SOLVENT PRESENT IN AN AMOUNT WITHIN THE RANGE OF FROM ABOUT 5% TO ABOUT 25% BY WEIGHT BASED ON THE TOTAL WEIGHT OF SAID COMPLEX AND SAID ALCOHOLIC SOLVENT; (D) AN ALKALIZING AGENT PRESENT IN AN AMOUNT SUFFICIENT HAVING 1 TO 3 CARBON ATOMS, SAID CHLORINATED HYDROCARBON SOLVENT BEING PRESENT IN AN AMOUNT SUCH THAT THE DYESTUFF SOLUTION CONTAINS FROM ABOUT 0.1 TO ABOUT 20 PARTS BY WEIGHT OF SAID COMPLEX PER 100 PER PARTS OF SAID HYDROCARBON SOLVENT; (D) AN ALKALIZING AGENT PRESENT IN AN AMOUNT SUFFICIENT TO SSURE THAT THE PH OF SAID DYESTUFF SOLUTION IS FROM ABOUT 2 TO ABOUT 7.5; AND (E) WATER PRESENT IN AN AMOUNT SUFFICIENT TO FORM A CLEAR, STABLE SOLUTION OF THE COMPLEX IN SAID SOLUTIO CONTAINING SAID CHLORINATED HYDROCARBON SOLVENT AND SAID LOWER ALCOHOLIC SOLVENT, WHEREBY THE RESULTING CLEAR, STABLE DYESTUFF SOLUTION IS CAPABLE OF PRODUCING A GREATER DEGREE OF BRIGHTNESS THAN CONVENTIONAL AQUEOUS DYESTUFF SOLUTIONS, THE SHORT DYEING TIME ACQUIRED WITH SAID DYESTUFF SOLUTIONS, THE SHORT DYEING AGE TO THE FIBER BEING DYED AND PERMITTING INCREASED DYED FIBER PRODUCTION. 